Photographic film unit with processing container



PHOTOGRAPHIC FILM UNIT WITH PROCESSING CONTAINER Filed May 12, 1958 E. H. LAND Sept. 11, 1962 2 Sheets-Sheet 1 COVER SHEET 1 EMULSION LAYER RECElVlNG LAYER SUPPORT FLUID EMULSION Sept. 11, 1962 E. H. LAND 3,053,659

PHOTOGRAPI-IIC FILM UNIT WITH PROCESSING CONTAINER Filed May 12, 1958 2 Sheets-Sheet 2 COVER SHEETv EMULSION LAYER RECEIVING LAYER INTENSIFYING LAYER SUPPORT OPAQUE COVER SHEET SUPPORT RECEIVING LAYER TRANSPARENT SUPPORT RECEIVING LAYER EMULSION LAYER OPAQUE SUPPORT ware Filed May 12, 1953, Ser. No. 734,613 12 Ciaims. (Cl. 96-45) United This invention relates to photographic processes and products, and, more particularly, to processes of the type wherein a photosensitive material is treated with a processing fluid distributed between a pair of superposed, confining layers, to photographic products including photosensitive materials useful in said processes, and to novel methods of forming said products.

Objects of the invention are: to provide novel and improved methods of producing a visible photographic image by treating a photosensitive material between a pair of superposed sheets with a fluid processing composition dis tributed in a thin layer between the sheets; to provide novel film assemblages, comprising a pair of superposed sheets and a layer of photosensitive material between said sheets, adapted to be employed in said processes; and to provide novel methods of manufacturing said film assemblages.

It has been the practice in photographic processes of the present type to introduce and spread the processing fluid between a pair of sheets in one of two general manners, either by spreading the fluid from a container introduced between the sheets or by feeding the fluid between the sheets as they are superposed by movement between a pair of pressure-applying members. The present invention has, as other objects, the provision of a method of introducing and spreading a processing fluid between a pair of sheets which are laminated together, from a compressible rupturable container located outside of the sheets and coupled with an edge of said sheets; the provision of a film assemblage adapted to be employed in the above process and comprising a pair of sheets laminated to one another by at least a layer comprising a photosensitive material; the provision of a novel method of forming a film assemblage of the above type including spreading a viscous photosensitive fluid in a thin layer between a pair of superposed sheets by movement of the sheets relative to and between a pair of pressure-applying members and thereafter attaching a container of a fluid composition, including a developer, to an edge of the sheets; and the provision of a film assemblage of the above type comprising other layers including a print-receiving layer and an X-ray intensifying layer.

Further objects of the invention are: to provide a method of processing a photosensitive layer laminated between two sheets, which method includes separating said photosensitive layer from one of said sheets by forcing a fluid composition to spread in a thin layer therebetween, adhering said one sheet to said photosensitive layer by said layer of fluid and separating said other sheet from said photosensitive layer; to provide a method as described wherein one sheet is transmissive to light actinic to said photosensitive layer, said other sheet is opaque to actinic light and said fluid includes a material for rendering a layer of said fluid opaque to actinic light; and to provide novel photographic film assemblages useful in the above methods and particularly adapted to exposure by penetrative radiation and exposure and processing in the light to produce visible photographic images.

Still other objects of the invention are: to provide methods of the above type wherein a fluid is spread between a pair of laminated sheets from a container located externally of the sheets by the application of compressive pressure to the container and sheets; and to provide a method of the type described employing a film unit adapted to the production of a photographic print and comprising multiple layers laminated together and wherein a container of the processing fluid is coupled with the film unit following exposure of the film unit and the fluid contents of the container are spread in a thin layer within the film unit by the application of compressive pressure to the coupled container and film unit.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a somewhat schematic sectional view of a film assemblage embodying the invention;

FIG. 2 is a somewhat schematic sectional view illustrating a method of forming the photographic film assemblage of FIGURE 1;

FIG. 3 is a fragmentary, sectional view of the film assemblage of FIGURE 1;

FIGS. 4 and 5 are sectional views illustrating steps in the processing of the film assemblage of FIGURE 1;

FIG. 6 is a sectional view illustrating another form of film assemblage embodying the invention;

FIG. 7 is a fragmentary, perspective view of a component of a film assemblage embodying the invention; and

FIGS. 8, 9 and 10 are sectional views of other embodiments of the film assemblage.

A number of photographic processes have been proposed which involve the spreading of a fluid composition between a pair of superposed sheets to effect the treatment of a layer of photosensitive material. These processes preferably involve the formation and development of a latent image in the photosensitive material and the production of a visible image by the transfer of image-forming substances produced as a result of the development of the latent image in the photosensitive material. In one form of process, a silver halide emulsion is exposed and subjected to a transfer-reversal process to produce a positive silver print in an image-receptive layer.

Photographic film assemblages proposed for use in this type of process have taken the form of two sheetlike elements superposed, or adapted to be superposed, with one another to provide confining layers between which a fluid processing composition is spread in a thin layer. One of the sheets provides a support for a layer of photosensitive material, such as a silver halide emulsion, while either sheet may comprise a support for an image-receptive layer. Depending on the method of exposure and the environment during processing of the photosensitive material, either or both sheets may be transparent, transmissive or opaque to actinic light, the latter being especially desirable if the assemblage of sheets is to be processed in the light. On the other hand, it may be desirable not to have the sheets spaced apart during exposure so that unless exposure is to be made by penetrative radiation, one of the sheets should be transparent. In order to process this latter type of film assemblage in the light, some provision must be made for preventing exposure of the photosensitive material located between the sheets and this usually comprises an envelope or some other type of covering means which is applied to the film assemblage following exposure and prior to removal into.

the light. In the assemblage of the present invention, the processing fluid is spread between the emulsion and the light-transmitting sheet and comprises a material for rendering the layer of processing fluid opaque to actinic light. This construction avoids the necessity for applying a covering means to the film assemblage following exposure.

The film assemblage of the invention comprises a unitary laminated structure, that is, two sheetlike elements adhered or laminated in superposition with one another by an intermediate layer comprising a photosensitive material such as a silver halide emulsion. The two elements are not merely arranged in superposition but are bonded together so that the standwich structure thus formed does not require or even permit separation of the elements for exposure and/or manipulation of the elements to bring them into superposition. The photosensitive silver halide emulsion is located between outer laminae of the sandwich and is adapted to be exposed, either through one of the outer laminae which is transparent or so formed as to transmit actinic light to the photosensitive material, or by penetrative radiation.

As previously noted a preferred practice has been to spread the fluid processing composition in a compressible container located between two of the superposed elements of a film assemblage, and compressing the container to cause the fluidcontents to be discharged between the elements. Thereafter the fluid is spread in a layer between the elements of the assemblage by applying compressive pressure progressively to the assemblage. In the assemblage of the invention, the fluid composition is also pro vided in a compressible rupturable container. However, the container is located outside of the elements, rather than between them, at one edge of the elements or the area of the layer of photosensitive material to be treated. The container is provided with a discharge mouth connected to the elements in a fluid-tight manner so that hydraulic pressure generated in the fluid within the con tainer tends to force the fluid between laminae of the film assemblage and to force the laminae apart, rupturing the bond therebetween.

Securing the container outside of the film assemblage provides a number of advantages residing both in the fabrication and the use of the present assemblage. For example, the laminated sandwich comprising the two sheets and layer of photosensitive material can be formed completely apart from the container of processing fluid, which then can be attached to the sandwich at a later time. Since the container is coupled with the sheets following their lamination to form the sandwich, the laminating process is simplified and can be accomplished readily and easily. For example, the sandwich can be produced by bonding a photosensitive sheet, including a preformed photosensitive layer, directly to another sheet employing the photosensitive layer as the bonding agent; or bonding of two sheets and forming the photosensitive layer can be accomplished in a single step by spreading a viscous fluid comprising a photosensitive material such as a gelatino silver halide emulsion in a layer between two superposed sheets.

Exposure of the assemblage is simplified since there are no sheets to be separated for exposure and then superposed for processing. Processing is simplified by virtue of the fact that neither the processing fluid nor the container need be introduced between a pair'of superposed sheets, and little manipulation of the sheets is required and the danger of exposure of the photosensitive material is reduced. An assemblage of this type can be made lighttight simply by using opaque sheets or layers on the outside of the emulsion layer, and is particularly suited for processes wherein exposure is to be made by X-rays or other penetrative radiation. The container of processing fluid may be easily and readily coupled with the laminated sandwich at any time prior to processing, thereby making the method and film assemblage of the invention particularly desirable for oral, dental or the like, X-ray work, wherein there is a reluctance to introduce a container of processing fluid, as a part of the film unit, into the mouth or other body cavity.

Reference is now made to FIG. 1 of the drawings wherein there is illustrated one form of photographic film assemblage embodying the invention, the relative thickness of the materials being exaggerated, in some instances, for clarity of illustration. The film assemblage is in the form of a laminated sandwich 10 comprising a support sheet 12, an image-receiving layer 14, a photosensitive layer 16 and a cover sheet or layer 18. Film assemblage 10 is preferably adapted to the production of a positive transfer image or print, hence the image-receiving layer 14.

Photosensitive layer 16 may comprise any of the photosensitive materials usually employed for photographic purposes such as the silver halides and other heavy metal salts capable of having a developable latent image formed therein by exposure, the ferric salts, or diazonium compounds; and the transfer image may be formed by any of the processes, such as are well known in the art, involving the development of a latent image in the photo sensitive layer and the transfer of image-forming substances produced as a result of the development of the latent image including, for example, the transfer of dyes or dye intermediates. For illustrative purposes, a preferred form of the film assemblage of the invention is described as being adapted to the production of a positive silver-transfer image by a silver halide diffusion-transfer reversal process, and comprises materials intended for this type of processing. Accordingly, photosensitive layer 16 comprises a silver halide emulsion and image-receiving layer 14- and support sheet 12 cooperate to provide a support for a positive silver print.

Sheet 12, in addition to being adapted to provide a support for a positive reflection print, is preferably opaque to light actinic to the silver halide of photosensitive layer 16, and may comprise any of the opaque sheet materials generally employed as a base for positive prints, for example, baryta paper. Cover sheet 18 provides an outer layer for sandwich 10 and, in the form shown, is transparent to actinic light and may comprise any of the usual transparent film base sheet materials including, for example, cellulose acetate, cellulose triacetate, regenerated cellulose film, polyvinyl alcohol, Mylar (trade name for polyethylene terephthalate resin), and Nylon type F8 (trade name for N-methoxymethyl polyhexamethylene adipamide). Cover sheet 18 is adapted to provide a support for layer .16 so that the layer may be stripped from the image-receiving layer following formation of a positive transfer print.

Sandwich 10 may be formed, for example as shown in FIG. 1, by superposing support sheet 12 including image-receiving layer 14, with cover sheet 18 and casting or spreading a viscous fluid, comprising a silver halide emulsion, in a thin layer between the cover sheet and image-receiving layer. Spreading of the emulsion can be accomplished by moving the two sheets into superposition between a pair of pressure-applying members, for example juxtaposed rolls 19, and, while moving the sheets through a convergent gap between the pressureapplying rolls, dispensing the fluid emulsion into the space between the sheets as the sheets move along converging paths into the gap between the pressure-applying members. The construction of sandwich 10 comprising a single exposure frame and area for receiving a transfer print lends itself readily to mass production methods, especially in view of the fact that layers of the sandwhich do not need to be separated to permit introduction of a processing fluid or container thereof. The sandwich may comprise a portion of a much larger sandwich or laminate formed easily and inexpensively by laminating extended lengths of wide sheet material. The emulsion layer is allowed to harden and individual sandwiches of the proper size are cut from the larger laminate. Assembly of each film unit or assemblage is com aosaes pleted simply by attaching acontainer of processing fluid to an edge of the sandwich.

The film assemblage of the invention is intended to be processed by a viscous fluid composition spread in a thin layer between laminae of the assemblage. This processing fluid is preferably provided in an elongated rupturable container, designated 20, attached or coupled with an edge of the assemblage and adapted to rupture and discharge its fluid contents in a single direction when subjected to compressive pressure, as by movement between a pair of pressure-applying members. Container 20 is formed, for example, as shown in US. Patent No. 2,543,181, issued to Edwin H. Land on February 27, 1951, by taking a single rectangular blank of a fluid-impervious, multi-layer sheet material and folding the blank medially. Thereafter, the end marginal portions and the longitudinal marginal portions 22 of the two folded faces are sealed to one another to provide a central cavity 24 for containing a fluid reagent 26. The longitudinal seal between longitudinal marginal portions 22 is preferably weaker than the end seals and is such that, upon application of a predetermined compressive force to the walls of the container, there will be generated within the fluid in the container hydraulic pressure suflicient to separate longitudinal marginal portions 22 throughout substantially their entire length.

The fluid-filled cavity 24 of container 20 is preferably at least equal in length to the width of the area or exposure frame over which the fluid composition is to be spread for processing the exposure frame. Container 20 is coupled or attached to an edge of sandwich in a fluid-tight manner so that there is no place for the fluid to flow from the container except between laminae of sandwich 10, and compression of the container and the resultant hydraulic pressure generated in the fluid contents of the container will force the fluid between laminae of the sandwich. A preferred means for attaching the container is illustrated in FIGS. 1, 3, 4 and 7 of the drawings and comprises a cover sheet 28 secured around the container and to sandwich 10. Cover sheet 23 comprises a single blank of sheet material preferably having a length dimension greater than that of container and the sandwich, and a width dimension substantially exceeding twice that of container 20. Cover sheet 28 is folded medially (lengthwise) in substantially the same manner as is the blank comprising container 20, the latter being attached between the two folded faces of cover sheet 28 which are preferably adhered to the 'walls of the container. The end marginal areas 30* of cover sheet 28 project beyond the ends of the container and are secured to one another, while the longitudinal marginal areas 32 of the cover sheet extend beyond and in the same direction as longitudinal marginal portions 22 of container 20 and are secured to the outer surfaces of sandwich '10, specifically, to support sheet 12 and cover sheet 18.

Cover sheet 28 is secured to sandwich 10 with longitudinal marginal portions 22 of container 20 located closely adjacent the edge of the sandwich to which longitudinal marginal areas 32 are secured, so that the fluid contents of the container may be forced directly therefrom between laminae of the sandwich. Materials suitable for cover sheet 28 include paper, laminated sheet materials, foils and plastic sheet materials. The bond between the' longitudinal marginal areas 32 and the edges of support sheet 12 and cover sheet 18 is preferably mechanically stronger than the bond between the laminae of the sandwich between which the fluid contents of the container are to be spread in order to insure rupture between laminae of the sandwich and proper spreading of the fluid processing composition within the sandwich.

The film assemblage of the invention is adapted to be processed, as shown in FIG. 4, by distributing a viscous fluid processing composition, carried in container 20, in a thin layer 38 between photosensitive layer 16 and cover 6 sheet 18. Accordingly, to insure spreading of the fluid between photosensitive layer 16 and cover sheet 18, the bond therebetween should be mechanically weaker than the bonds between any of the other laminae, specifically weaker than the bonds between photosensitive layer 16 and image-receiving layer 14 and between the receiving layer and support sheet 12. Spreading of the fluid and the attendant separation of the cover sheet from the photosensitive layer are accomplished by progressively applying compressive pressure, first to the container and then to areas of the sandwich succeeding from the edge thereof adjacent the container toward the opposite edge of the sandwich. The means for applying compressive pressure may take the form of a pair of members, such as a pair of juxtaposed rolls 34 and 36 (see FIG. 4), a plate and roll or a pair of members having a narrow gap therebetween through which the assemblage is moved. In the form shown, pressure-applying rolls 34 and 36 are preferably biased toward one another so as to compress the container sufiiciently to effect a substantially complete discharge of its fluid contents as the container is moved between the rolls. As compressive pressure is initially applied to the container commencing in the region of the longitudinal edge thereof opposite longitudinal marginal portion 22, hydraulic pressure in the fluid causes longitudinal marginal portions 22 to separate so that the fluid fiow toward and into contact with an edge of sandwich 10. Continued movement of the container and assemblage between the pressure-applying members tends to force the fluid between the laminae having the weakest bond, in this case photosensitive layer 16 and cover sheet 18. This causes the photosensitive layer and cover sheet to be separated, permitting spreading of the fluid in a thin layer therebetween.

The bond between the longitudinal marginal portions 22 is adapted to rupture simultaneously throughout a length substantially equal to the length of the fluidcarrying cavity 24, which, in turn, is substantially equal to the width of the area or exposure frame of the photm sensitive layer over which the fluid is to be distributed. To insure the simultaneous rupture of the container throughout the length of cavity 24 and to permit uniform and controlled spreading of the fluid, there is provided in the fluid a material which imparts thereto a predetermined high viscosity. A further control is had over the area over which the fluid is to be spread and the uniformity and thickness of the layer of fluid by providing the pressure-applying members or rolls with fluid-spreading surface portions and cooperating portions on one of the members, such as shoulders on the ends of one of the rolls at opposite sides of the fluid-spreading surface portions, adapted to engage the margins of the sandwich and maintain the fluid-spreading surfaces of the rolls spaced apart a predetermined amount greater than the thickness of the margins -of the two sheets. This arrangement tends to prevent separation of the photosensitive layer and the cover sheet at their margins and contributes to confining the spread of processing fluid to a predetermined area between the margins of the sheets as well as to the light-sealing of the assemblage.

The form of film assemblage shown in FIG. 1 is preferably adapted to the production of a positive silver print in or on image-receiving layer 14 and, for this purpose, the image receiving layer comprises, for example, a silver precipitating agent such as a material from the class consisting of the sulfides, selenides and selenosulfides dispersed in a silica matrix and coated on a water-impervious base. For a more detailed description of the formulation and composition of image-receiving layers of this type, reference may be had to US. Patent No. 2,774,667, issued to Edwin H. Land et al. on December 18, 1956. Image-receiving layer 14 is carried on support sheet 12, adapted to provide a support for a positive reflection print and which may comprise baryta paper having an outer coating or layer which. is opaque to light actinic to the photosensitive layer. Photosensitive layer 16 comprises a gelatino silver halide emulsion and forms a lamina between cover sheet 18 and image-receiving layer 14 which functions to adhere or bond the cover sheet and the image-receiving layer to one another. Photosensitive layer 16 may be formed in any of the known manners on cover sheet 18 and laminated to image-receiving layer 14, for example, by being wet or softened and then pressed into contact with the image-receiving layer. In the preferred method shown in FIG. 2, the photosensitive layer is formed and the cover sheet and image-receiving layer are laminated together in a single operation by spreading the silver halide emulsion as a viscous fluid in a thin layer between the superposed cover sheet and image-receiving layer and allowing the emulsion layer to harden. An example of a silver halide emulsion suitable for spreading in a thin layer between cover sheet 18 and image-receiving layer 14 by movement of the cover sheet and image-receiving layer in superposition between a pair of pressure-applying members is one consisting of:

Dehydrated emulsion (Du Pont DH) grams 50 Water cc 50 high viscosity solution of deacetylated chitin cc Fluid processing compositions suitable for use in the invention are described in detail in the above-mentioned Patent No. 2,543,181, and generally comprise an alkaline aqueous solution of a silver halide developer such as hydroquinone, a silver halide complexing agent such as sodium thiosulfate and a film-forming material such as sodium carboxymethyl cellulose, which retains its viscosity-imparting and film-forming properties in an aqueous alkaline solution, so that the fluid agent, once its ingredients have been mixed and have obtained an equilibrium, remains substantially viscous for any given temperature for long periods of time. The film-forming material is preferably contained in the fluid agent in suitable quantities to impart thereto a viscosity in excess of 1000 centipoises at a temperature of 20 C., and preferably of the order of 1000 to 200,000 centipoises at said temperature.

This fluid processing composition is spread on the differentially exposed photosensitive layer 16 between it and cover sheet 18 and allowed to remain during a predetermined processing period, during which it permeates the silver halide layer, reducing exposed silver halide to silver and forming a water-soluble complex from unreduced silver halide, this complex diffusing to the image-receiving layer 14 where it is reduced to silver to form a visible print. For further examples and details of materials useful in processes of this type, reference is again made to the above-mentioned Patent No. 2,543,181. Permeation of the photosensitive layer by the processing fluid can be facilitated by the addition of a wetting agent to the processing fluid. For example, to a quantity of processing fluid comprising cc. of water may be added 2 cc. of polyoxypropylene polyoxyethylene condensate, sold by Wyandott Chemical Corporation under the trade name Pluronic L44.

Film assemblage 10 is preferably adapted to be moved directly into the light as the processing fluid is spread in a layer between photosensitive layer 16 and cover sheet 18. Since cover sheet 18 is transparent or at least transmissive to actinic light, provision must be made for preventing actinic light from passing through cover sheet 18 and layer of processing fluid 38 to the photosensitive layer. This can be readily accomplished by providing a dye or pigment in layer of processing fluid 38 which is capable of absorbing light actinic to the photosensitive layer. A suitable material for this purpose is lampblack which has proven effective to prevent exposure of the photosensitive material when added to the processing fluid in the amount, for example, of 3% by weight.

At the end of a predetermined processing period, cover sheet 18 along with photosensitive layer 16 and layer of processing composition 38 are stripped (see FIG. 5)

'8 from image-receiving layer 14 and support sheet 12, the latter together comprising a finished positive photographic print. As the water in the processing fluid is absorbed into the various layers and sheets comprising the assemblage, the film-forming agent in layer of processing fluid 38 tends to solidify so as to adhere photosensitive layer 16 to cover sheet 18. Photosensitive layer 16 is softened by the porcessing fluid, thereby weakening the bond between the photosensitive layer and image-receiving layer 14, so that the bond is weaker than the adhesive force of layer of processing fluid 38 and permits the photosensitive layer to be stripped, along with layer 38 and cover sheet 18, from the print comprising image-receiving layer 14 and support sheet 12. The deacetylated chitin present in the emulsion layer is hardened by the alkali in the processing fluid and is included in the emulsion layer for the purpose of imparting strength and flexibility to the emulsion layer suflicient to permit the emulsion layer to be stripped as a unit from the image-receiving layer. It may be desirable, in order to insure a complete spread of the processing fluid over a predetermined area of the photosensitive layer, to provide processing fluid 26 in an amount in excess of that required, and, accordingly, means are provided for collecting or trapping any excess fluid which may be squeezed from between the photosensitive layer and cover sheet. One form of fluid-trapping means is shown in FIGS. 1 and 3 and comprises a pair of sheets 40 secured to the trailing edges of support sheet 12 and cover sheet 18 opposite container 20 so as to project beyond the assemblage away from the container. Spacer elements 42 are provided between sheets 40 at the margins of the assemblage for spacings the pressure-applying members apart by an amount substantially greater than the combined thicknesses of sheets 40 as the latter are moved between the pressure-applying members. In this manner a space is provided between sheets 40 within which fluid squeezed from between laminae of assembly 10 is collected and retained.

Another form of film assemblage, designated 44, is illustrated in FIG. 6 of the drawings. Film assemblage 44 is particularly adapted to exposure by penetrative radiation, and particularly X-radiation, and is adapted to be processed for producing a reflection print. Assemblage 44 comprises a support sheet 46, an intensifying layer 48, an image-receiving layer 50, a photosensitive layer 52 and a cover sheet 54, all laminated to one another in the order set forth to provide the assemblage. Support sheet 46 and cover sheet 54 can be formed of any conventional film base material including paper, plastics and the like, and are preferably opaque to light actinic to photosensitive layer 52. Intensifying layer 48 comprises one of the fluorescent materials or phosphors generally used for such purposes and which, when excited by penetrative radiation, emit light actinic to the photosensitive layer 52. Receiving layer 50 and photosensitive layer 52 may comprise any of the materials previously noted as being suitable for incorporation in such layers, and particularly materials for effecting the formation of a positive silver image by a diffusion-transfer reversal process. Assemblage 44 is adapted to production in the manner described above. Intensifying layer 48 and image-receiving layer 50 are coated in turn on support sheet 46 and this subassemblage is then laminated with cover sheet 54 by a layer 52 of a gelatino silver halide emulsion provided between image-receiving layer 50 and cover sheet 54.

In the embodiment illustrated in FIG. 6, image-receiving layer 50 is shown as being disposed between intensifying layer 48 and photosensitive layer 52. This arrangement has little or no adverse effect on image resolution since the image-receiving layer can be extremely thin, on the order of one thousandth of an inch or less, and is desirable because the intensifying layer is located behind the image-receiving layer in the positive transfer print and makes a good background for the silver image, especially if the intensifying layer comprises a fluorescent material of the type which emits white light when excited by ultraviolet radiation. With the embodiment shown, a fluid processing composition, such as has been described above, may be distributed between cover sheet 54 and emulsion layer 52 for processing the assemblage to produce a positive silver-transfer image in image-receiving layer 50. The fluid composition may also be distributed between emulsion layer 52 and receiving layer 50 for producing a transfer image in the receiving layer, or film assemblage 44 may be adapted to the production of a silver-transfer image by a process, such as described in US. Patent No. 2,662,822, issued to Edwin H. Land on December 15, 1953, wherein the silver-transfer image is formed in the layer of fluid processing composition spread between the processing fluid and the image-receiving layer. In this process the processing fluid is retained on the image-receiving layer when the photosensitive layer is stripped therefrom and provides a support for the transfer image. In this embodiment the bond between imagereceiving layer 50 and emulsion layer 52 would necessarily be mechanically weaker than the bond between any other pair of adjacent laminae so that the fluid would spread between the photosensitive and image-receiving layers and the image-receiving layers and photosensitive layers would be so composed that the layer of processing fluid adheres to the image-receiving layer when the photosensitive layer is stripped therefrom. Other modifications may be made in the order and arrangement of layers in assemblage 44, particularly with regard to the location of intensifying layer 48. This layer may be located between the photosensitive and image-receiving layers or between the photosensitive layer and cover sheet 54. In still another embodiment of assemblage 44, the intensifying phosphor may be incorporated in the emulsion itself, thereby eliminating the necessity for a separate intensifying layer. Filmassemblage 44 is particularly well suited for use in roentgenogr-aphic processes wherein the photosensitive material is required to be introduced into a body cavity, for example the mouth, and it is not desirable to introduce a container of a processing fluid along with the film assemblage. Since assemblage 44 does not require any handling in the dark, the container 28 and its cover sheet 28 (see FIG. 7) may be attached to the film assemblage following exposure thereof. To facilitate this attachment, the inner surfaces of longitudinal marginal areas 32 of cover sheet 28 and marginal portions along one edge of support sheet 46 and cover sheet 54 are provided with a coating of an adhesive, preferably of the type which has a strong aflinity only for itself. This construction permits the edge portion of the assemblage having the adhesive coating to be introduced, following exposure of the assemblage, between longitudinal marginal areas 32 and to be effectively joined therewith by pressing the longitudinal marginal areas into contact with the edge portion of the assemblage. Thereafter, the assemblage can be processed in the manner described by progressively applying compressive pressure, as, for example, by movement between a pair of pressure-applying rolls.

Reference is now made to FIG. 8 wherein there is illus trated another form of film assemblage embodying the invention and adapted to, exposure by penetrative radiation for producing a positive transfer print or transparency adapted to be viewed by transmitted light. This assemblage, designated 56, is shown as comprising, in sequence, an opaque support sheet 58, an intensifying layer 60, a photosensitive layer 62, an image-receiving layer 64, a transparent or light-transmitting support sheet 66 and a cover sheet 68 which is opaque to light actinic to the photosensitive layer. Support sheet 66 and image-receiving layer 64 comprise the support for a transparency produced by the exposure and processing of assemblage 56, and, accordingly, support sheet 66 preferably comprises one of the conventional transparent film base materials. Opaque cover sheet 68 is required for preventing exposure of the photosensitive material through support a 2 1t) a sheet 66 and is adhered to the support sheet in a lighttight manner, preferably by an adhesive which will permit the cover sheet to be readily and easily stripped from the support sheet when processing of the assemblage is complete. The bonds between the various laminae of the assemblage are so related that the fluid processing composition is spread between either photo-sensitive layer 62 and image-receiving layer 64 or between photosensitive layer 62 and intensifying layer 60'. In an alternative embodiment of assemblage 56, intensifying layer 60 may be located between the image-receiving and photosensitive layers, in which case the fluid may be spread.

on either side of the photosensitive layer or intensifying layer.

Another form of film assemblage adapted to exposure by penetrative radiation and to processing for producing a positive transfer print adapted to be viewed by transmitted light is shown at '70 in FIG. 9. Assemblage 70 comprises, in the order given, an opaque support sheet 72, an intensifying layer 74, a photosensitive layer 76, an opaque stripping layer 78, an image-receiving layer and a support sheet 82. Support sheet 82 and receiving layer 84) are adapted to comprise a transparency and, accordingly, support sheet 82 is formed of a transparent material of the type generally used for film bases. Assemblage '70 comprises an intermediate stripping layer 78 disposed between transparent support 82 and photosensitive layer '76 for preventing exposure of the photosensitive layer. Intermediate stripping layer 78 comprises a waterpermeable or water-soluble material, for example, sodium carboxymethyl cellulose, rendered opaque to actinic light by a dye or a pigment, for example lampblack, dispersed in the film-forming material, which is opaque to actinic light and is adapted to be stripped along with the photosensitive layer from the image-receiving layer containing a transfer image produced by diffusion through layer 78. The processing fluid can be spread in a layer, either between photosensitive layer 76 and opaque stripping layer 78 or between intensifying layer 74 and photosensitive layer 76. In an alternative method of processing, the processing fluid may be spread between opaque stripping layer '78 and receiving layer 80, particularly if the opaque stripping layer comprises a water-soluble material.

Still another form of film assemblage embodying the invention is shown at 84 in FIG. 10 and is adapted to exposure by non-penetrative radiation and to the production of a transparent positive print adapted to be viewed in transmitted light. Assemblage 84 comp-rises, in the order given, an opaque support sheet 86, a photosensitive layer 88, an image-receiving layer and a transparent support sheet 92 which cooperates with the image-receiving layer to comprise a support for a positive transparent print. Assemblage 84 also comprises a cover sheet 94 which is opaque to light actinic to the photosensitive layer and is adhered to the outside of transparent support sheet 92. by an adhesive which permits the cover sheet to be stripped from the transparent support and reapplied by the application of pressure. In the form shown, cover sheet 94 is substantially longer than assemblage 84, having an end section 96 folded transversely to provide a cover sheet for a container 98 of processing fluid. Opaque cover sheet 94 is spaced apart from assemblage 84, in the manner shown in FIG. 10, during exposure of the photosensitive layer through support sheet 92. [Following exposure of the photosensitive layer, compressive pressure is applied progressively to the container and then to the film assemblage for simultaneously spreading the fluid contents of the container between laminae of the assemblage and re-applying cover sheet 94 to support sheet 92 in a lighttight manner so that the assemblage may be moved into the light during processing. The processing fluid can be spread in a layer within assemblage 84 on either side of the emulsion layer and this is determined by the relative mechanical strengths of the bonds between the various laminae of the assemblage.

Since certain changes may be made in the above product and process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A photographic film unit comprising, in combination, a support layer, a photosensitive layer including a material selected from the class consisting of the photosensitive heavy metal salts, ferric salts and diazonium compounds suspended in a supporting medium and an image-receiving layer, said layers being bonded together in face-to-face contact to form a laminate in which said supporting medium acts as the bonding agent, the bond between said layers comprising an area thereof which extends to an edge of said laminate and is exposed and treated with a processing fluid, a collapsible container carrying a viscous fluid processing composition including an agent capable of reacting with said area of said photosensitive layer, following exposure thereof, to produce a visible image, said container having lips defining a discharge passage through which the fluid contents of said container can be ejected and means for securing said container at said edge of said laminate exteriorly thereof and forming a substantially fluid-tight seal between said lips and portions of the outer layers of said laminate at said edge, whereby hydraulic pressure generated within said fluid will tend to force said fluid between those two layers of said laminate between which the bond forces are weakest.

2. The photographic film unit of claim 1 wherein said photosensitive layer comprises a gelatino silver halide emulsion and said fluid composition includes a silver halide developer.

3. A photographic film unit comprising, in combination, a laminate including a first sheet, a second sheet superposed with said first sheet and including an imagereceiving layer located between the outer surfaces of said sheets and a photosensitive layer located between said sheets, said photosensitive layer including a photosensitive material selected from the class consisting of the heavy metal salts, ferric salts and diazonium com.- pounds in a supporting medium, said layers and said sheets being bonded together by the material comprising said layers in face-to-face contact over an area, extending to an edge of said laminate, to be exposed and then treated with a fluid distributed thereover in contact with said photosensitive layer in said area, a collapsible container carrying a viscous fluid processing composition including an agent capable of reacting with said photosensitive material in said area following exposure thereof to produce a visible image, said container having lips defining a discharge passage through which the fluid contents of said container can be ejected, and means for securing said container exteriorly of said laminate to exterior portions of said sheets at said edge and forming a substantially fluid-tight seal between said lips and said sheets, whereby hydraulic pressure, generated within said fluid, will tend to force said fluid between said sheets at said edge.

4. The photographic film unit of claim 3 wherein said container comprises a rectangular blank of sheet material folded intermediate its sides to provide two sections sealed to one another at their margins and forming a cavity for said fluid processing composition and said means for securing said container to said laminate comprises a rectangular cover sheet folded intermediate its sides to provide two cover sections adhered in surrounding relation to said container and having marginal portions extending in the same direction as said lips of said container, said marginal portions of said cover sections being attached to said sheets of said film unit at said edge.

5. The photographic film unit of claim 3 wherein the 12 bonding forces between said photosensitive layer and said first sheet are substantially weaker than the bonding forces between any other of said layers and sheets of said laminate.

6. The photographic film unit of claim 3 wherein said photosensitive layer comprises a gelatino silver halide emulsion and said fluid composition includes a silver halide developer.

7. The photographic film unit of claim 3 wherein said first sheet transmits light actinic to said photosensitive material, said second sheet is opaque to actinic light, and said fluid includes a material for absorbing actinic light and rendering a layer of said fluid substantially opaque to actinic light.

8. The photographic film unit of claim 3 wherein said fluid includes a viscous film-forming agent capable, when spread in a layer over said area between said photosensitive layer and one of said sheets, of adhering said photosensitive layer to said one sheet during subsequent separation of said first and second sheets.

9. The photographic film unit of claim 3 wherein said first and second sheets are bonded to one another by said photosensitive layer, and the bonding forces holding together said photosensitive layer and said second sheet are stronger than the bonding forces holding together said photosensitive layer and said first sheet.

10. The method of producing a photographic film unit comprising a photosensitive layer and a fluid composition provided for spreading in a layer of predetermined area for permeation into said photosensitive layer to effect the production of a visible image in said film unit, said method comprising spreading, in a layer over a predetermined area between a pair of sheets, a film-forming agent including a photosensitive material suspended in said agent and selected from the class consisting of the heavy metal salts, ferric salts and diazonium compounds, said layer of said film-forming agent and said photosensitive material comprising said photosensitive layer for bonding said sheets to one another and being spread so as to cover said predetermined area extending to an edge of said sheets to form a laminate, and attaching a rupturable container, having a pair of lips sealed together to provide a discharge mouth and containing a quantity of fluid composition including an agent capable of reacting with said photosensitive material following exposure thereof to produce a.- visible image, to the exterior of portions of said sheets at said edge by means providing a fluid-tight seal between said lips and portions of said sheets.

11. The method of claim 10 wherein a stronger bond is formed between said photosensitive layer and one of said sheets than between said photosensitive layer and the other of said sheets.

12. The method of claim 10 wherein said photosensitive layer is exposed by actinic radiation transmitted through one of said sheets prior to attachment of said container to said sheets.

References Cited in the file of this patent UNITED STATES PATENTS 1,499,230 Lage June 24, 1924 1,998,584 Kelley Apr. 23, 1935 2,565,377 Land Aug. 21, 1951 2,565,378 Land Aug. 21, 1951 2,600,064 McCune June 10, 1952 2,627,460 Land Feb. 3, 1953 2,647,055 Land July 28, 1953 2,778,269 Bartlett Jan. 22, 1957 2,823,122 Land Feb. 11, 1958 OTHER REFERENCES Ellis: Patent Claims; Baker et al., New York (1949), sections 374 and 376, pages 475-81. 

1. A PHOTOGRAPHIC FILM UNIT COMPRISING, IN COMBINATION, A SUPPORT LAYER, A PHOTOSENSITIVE LAYER INCLUDING A MATERIAL SELECTED FROM THE CLASS CONSISTING OF THE PHOTOSENSITIVE HEAVY METAL SALTS, FERRIC SALTS AND DIAZONIUM COMPOUNDS SUSPENDED IN A SUPPORTING MEDIUM AND AN IMAGE-RECEIVING LAYER, SAID LAYERS BEING BONDED TOGETHER IN FACE-TO-FACE CONTACT TO FORM A LAMINATE IN WHICH SAID SUPPORTING MEDIUM ACTS AS THE BONDING AGENTS, THE BOND BETWEEN SAID LAYERS COMPRISING AN AREA THEREOF WHICH EXTENDS TO AN EDGE OF SAID LAMINATE AND IS EXPOSED AND TREATED WITH A PROCESSING FLUID, A COLLAPSIBLE CONTAINER CARRYING A VISCOUS FLUID PROCESSING COMPOSITION INCLUDING AN AGENT CAPABLE OF REACTING WITH SAID AREA OF SAID PHOTOSENSITIVE LAYER, FOLLOWING EXPOSURE THEREOF, TO PRODUCE A VISIBLE IMAGE, SAID CONTAINER HAVING LIPS DEFINING A DISCHARGE PASSAGE THROUGH WHCIH HE FLUID CONTENTS OF SAID CONTAINER CAN BE EJECTED AND MEANS FOR SECURING SAID CONTAINER AT SAID EDGE OF SAID LAMINATE EXTERIORLY THEREOF AND FORMING A SUBSTANTIALLY FLUID-TIGHT SEAL BETWEEN SAID LIPS AND PORTIONS OF THE OUTER LAYER OF SAID LAMINATE AT SAID EDGE, WHEREBY HYDRAULIC PRESSURE GENERATED WITHIN SAID FLUID WILL TENDER TO FORCE SAID FLUID BETWEEN THOSE TWO LAYERS OF SAID LAMINATE BETWEEN WHICH THE BOND FORCES ARE WEAKEST. 